On the first day of what was to be his trial at Southwark crown court, the Liberal Democrat MP entered a plea of guilty over claims that his ex-wife Vicky Pryce took speeding points for him a decade ago.
The charge relates to an incident in March 2003 when Huhne's car was allegedly caught by a speed camera on the motorway between Stansted Airport in Essex and London.
It is alleged that between March 12 and May 21, 2003, Pryce, falsely informed police that she was the driver of the car so Huhne could avoid prosecution.
58-year-old Huhne resigned as energy and climate change secretary after he was charged, but had stayed on as Liberal Democrat MP for Eastleigh.
In a statement outside court following his guilty plea, Huhne said, "Having taken responsibility for something that happened 10 years ago, the only proper course of action for me is to resign my Eastleigh seat in Parliament, which I will do shortly."
Huhne was granted unconditional bail and will be sentenced at a later date.
